Adjustable oil well crank arm



Feb. 4, 1936. c. EURIT ADJUSTABLE OIL WELL CRANK ARM COUNTERWEIGHT Filed Aug. 24, 1935 3 W0 0mm 622 Zara? I "XMMI Patented Feb. 4, 1936 UNITED. STATES ADJUSTABLE OIL WELL CRANK ARM COUNTERWEIGHT Carl Eurit, Tulsa, Okla.

Application August 24, 1933, Serial No. 686,602. 10 Claims. (01. 74 -591) I This invention relates to certain new and useful improvements in adjustable oil well crank arm counter-balances. 1

Counter-balance weights for attachment to the crank arm of oil well pumping shafts or pumping rigs for counter-balancing the weight of sucker rods and the like are usually designed for attachment to a crank arm of a particular form usually having pointed or oval ends and such counter-balances being possessed of great weight, difiiculty and inconvenience are experienced in shifting the counter-balance when disengaged from the crank to a position spaced from the jack post, the primary object of this invention residing in the provision of a counter-balance and cooperating filler shoes designed for attachment to cranks of different forms and to be separated from the crank and remain in position, with respect to the jack post and permit free rotary movement of the crank arm independently thereof for repairs or adjustments.

A further object of the invention is to provide an adjustable oil well crank arm counter-balance wherein parts of the counter-balance are adapted to have filler shoe segments or the like designed for intimate contact with the'free' swinging end of the crank arm interposed between the crank arm and adjacent-counter-balance parts to render the counter-balance universal in its attachment to crank arms of different forms.

It is a further importantobject of this invention to so design the counter-balance whereby when the two connected weight members thereof are disengaged from the crank arm, they may be collapsed and supported, upon an adjacent block without disturbing its relative position with respect to the jack post and permit free rotation of the crank arm independently of the counterbalance for the purpose desired.

With the above and other objects in view that will become apparent as the nature of the invention is better understood, the same consists in thenovel form, combination and arrangement of parts hereinafter more fully described, shown in the accompanying drawing and claimed.

In the drawing:- Figure 1 is a side elevational view of the counter-balance engaged with the crank arm and illustrating the connections between the weight,

members of the counter-balance and the-filler shoe segments interposed between the counterbalance and crank arm; I 1

Figure 2 is a side elevational view showing the weight members of the counter-balance separated and disengaged from the crank arm and in position to permit free rotation of the crank arm;

Figure 3 is a side elevational view of one of the filler shoe segments; and

Figure 4 isan inner face view of the filler shoe 5 segment showing the concaved seat for intimate embracing contact with a side portion of the crank arm. v

Referring more in detail to the accompanying drawing, there is illustratedan adjustable .oil well 10 crank arm zcounter-balance, the crank arm' I ll being provided with spaced openings .II for selective reception of crank pins and said crank arm is illustrated as being of oval or curved form at l2 at its outer end. '15

The counter-balance comprises a pair of weight members l3 having curved lower sides and outer ends and straight line mating inner'ends II, the two weight members [3 being connected together adjacentthe lower curved sides at the inner ends 29 by a link l5 that is pivotally connected at its ends as at IE to the weight members. A screw device operating similarly to a turn buckle connectsthe upper portions of the inner ends 01' the weight members for drawing the same into 25 assembly relation and alsofor positively separating the same and includesoppositely threaded end screw. portions .11 provided with an 11.. .omediate operating nut I 8 with the outer ends of the screw portions I 1 threaded into bearing 30 blocks l9 in the upper'edge portions of the inner ends of the weight members.

The upper sides. oiv the weight members I 8 of the counter-balance are each provided with a filler shoe receiving seat 20 adjacent the screw 35 connection between the weight members for the reception of removable and inter-changeable filler shoe segments 2| shown in' detail in Figures 3 and 4 and having curved lower edges 22 received on the seat 20 with a grooved upper face 40 23 to receive and embrace the curved end I2 01' the crank arm H) as shown in Figure 1. A yoke strap 24 is pivotally connected as at 25 to the upper side of each weight member l3 outwardly of the. fillershoe receiving seat 20 and the inner 45 side of each yoke strap24-at its upper end is of arcuate form as at 26 for engagementwithr the adjacent portion of the bearing arm of the crank 10 with the upper terminal ends 2'! of the yoke strap secured together by a nut and bolt combl- 5O nation 28.

The counter-balance is illustrated in Figure 1 as assembled on a crank arm, the filler shoe segments 2| beinginterposed between the weight members I3 and the outer curved end l2 oi the crank arm and it is to be understood that the said segments 2| are removable and interchangeable for substitution of filler shoe segments of other forms to accommodate the universal'mounting of a counter-balance of standard construction upon'crank arms of different forms or designs. ihe counter-balance is illustrated in Figure 2 as disengaged from the crank arm in and by locating the pivotal link connection 15 between the weight members l3 adjacent the lower ends thereof, the screw device connecting the upper ends of the weight members may be operated for expanding the same a sufficient distance apart to space them from the free swinging end of the crank arm, rendering it unnecessary to transport or shift the counter-balance from its position relative to the jack post, the crank arm being free for rotation independently of the counter balance for repair work or adjustment.

From the above detailed description of the invention, it is believed that the construction thereof will at once be apparent and while there is herein shown and described the preferred embodiment of the invention, it is nevertheless to be understood that minor changes may be made therein without departing from the spirit and scope of the invention as claimed.

I claim:-

l. A detachable counter-balance adapted for universal attachment to crank arms of different forms of well pumping rigs in the plane of said crank arms comprising a pair of weight members, yoke straps carried thereby and adapted to be engaged with one end of the crank, arm for attaching thecounter-balance thereto, removable" filler shoe segments interposed between the weight members and the other end of the crank arm, each of said filler shoe segments having a lower face tofit in a complementary recess in the weight members, and an upper face shaped to intimately contact the free end of the'crank arm with which the counter-balance is adapted to be used.

2. A detachable counter-balance adapted for universal attachment to crank arms of different forms of well pumping rigs comprising a pair of weight members, yoke straps carried thereby for attaching the counter-balance to a crank arm, removable filler shoe segments interposed between the weight members and the free end of the crank arm, a link connection between the lower ends of the weight members permitting pivotal separation thereof and displacement of the yoke straps a sufficient distance apart whereby the crank arm may freely rotate out of contact with the counter balance and without positioning the counter-balance remote to the crank arm, and each of said shoe segments having a lower face shaped to fit in a complementary recess in the weight members and an upper face shaped to intimately contact the free end of a crank arm with which the counter-balance is adapted to be used.

3. A detachable counter-balance adapted foruniversal attachment to crank arms of different forms of well pumping rigs, comprising a pair of weight members, yoke straps carried thereby for attaching the counter-balance to a crank arm, removable filler shoe segments interposed between the weight members and the free end of the crank arm, a screw connection between the weight members for effecting. positive movement thereof towards" and away from each other in mounting the counter-balance on a crank arm, each of said segments having a lower face shaped to fit in members and an upper face shaped to intimately posed upper and lower a complementary recess in the weight contact the free end of a crank arm with which the counterbalance is adapted to be used.

4. A counter-balance comprising a pair of weight members pivotally connected together adjacent their lower ends, means between the weight members for positively moving the upper ends thereof towards and away from each other; on the pivotal connection, the adjacent edges of the upper ends of the weight members being cut away to provide a seat adapted to receive interchangeable filler shoes.

5. A counter-balance comprising a pair of weight members pivotally connected together adjacent their lower ends, means between the weight members for positively moving the upper ends thereof towards and away from each other on the pivotal connection, the adjacent edges of the upper ends of the weight members being cut away to provide a seat adapted to receive interchangeable filler shoes, each shoe being formed of segments.

6. A counter-balance comprising a pair of weight members pivotally connected together adjacent their lower ends, means between the weight members for positively moving the upper ends thereof toward and away from each other on the pivotal connection, the adjacent edges of the upper ends of the weight member being cut away to provide a seat, a filler shoe comprising segments removably mounted in the seat with the upper faces of said segments adapted for intimate contact with the adjacent free end of a well rigging crank arm, and means carried by the weight members for attaching the same to such arm;

'7. A counter-balance as set forth in claim 4, characterized by the means for moving the weight members on their pivots comprising a screw rod reversely threaded at opposite ends into the weight members and means on the screw rod intermediate its ends to facilitate rotation thereof.

8. A counter-balanceas set forth in claim 5, characterized by the means for moving the weight members on their pivots comprising a screw rod reversely threaded at opposite ends into the weight members and means on the screw rod intermediate its ends to facilitate rotation thereof.

9. As an article of manufacture, a preformed filler shoe segment adapted for use in connection with one portion of a counter-balance for a well rigging crank arm, the said segment having opfaces, the lowermost of said faces being contoured to fit a complementary recess in a portion of such a 'counter-balance, and the uppermost of said faces being shaped to partially embrace a portion of the lower end of a crank arm and the said segment adapted to fill the space between said portions of the counter-balance and crank arm in connection with which it is used.

10. A counterbalance for oil well pumping rigs comprising a weight member and instrumentali- -ties including tension elements for detachably embrace at least a portion of said arm.

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upper portion opposite 

